FI20195098A1 - System and method for detecting a wave occurring in/on a membrane - Google Patents
System and method for detecting a wave occurring in/on a membrane Download PDFInfo
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- FI20195098A1 FI20195098A1 FI20195098A FI20195098A FI20195098A1 FI 20195098 A1 FI20195098 A1 FI 20195098A1 FI 20195098 A FI20195098 A FI 20195098A FI 20195098 A FI20195098 A FI 20195098A FI 20195098 A1 FI20195098 A1 FI 20195098A1
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- membrane
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- wave
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Classifications
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B11/00—Measuring arrangements characterised by the use of optical techniques
- G01B11/02—Measuring arrangements characterised by the use of optical techniques for measuring length, width or thickness
- G01B11/06—Measuring arrangements characterised by the use of optical techniques for measuring length, width or thickness for measuring thickness ; e.g. of sheet material
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B3/00—Apparatus for testing the eyes; Instruments for examining the eyes
- A61B3/10—Objective types, i.e. instruments for examining the eyes independent of the patients' perceptions or reactions
- A61B3/1005—Objective types, i.e. instruments for examining the eyes independent of the patients' perceptions or reactions for measuring distances inside the eye, e.g. thickness of the cornea
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B8/00—Diagnosis using ultrasonic, sonic or infrasonic waves
- A61B8/10—Eye inspection
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B17/00—Measuring arrangements characterised by the use of infrasonic, sonic or ultrasonic vibrations
- G01B17/02—Measuring arrangements characterised by the use of infrasonic, sonic or ultrasonic vibrations for measuring thickness
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B9/00—Measuring instruments characterised by the use of optical techniques
- G01B9/02—Interferometers
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01H—MEASUREMENT OF MECHANICAL VIBRATIONS OR ULTRASONIC, SONIC OR INFRASONIC WAVES
- G01H9/00—Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves by using radiation-sensitive means, e.g. optical means
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B3/00—Apparatus for testing the eyes; Instruments for examining the eyes
- A61B3/10—Objective types, i.e. instruments for examining the eyes independent of the patients' perceptions or reactions
- A61B3/16—Objective types, i.e. instruments for examining the eyes independent of the patients' perceptions or reactions for measuring intraocular pressure, e.g. tonometers
- A61B3/165—Non-contacting tonometers
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/0093—Detecting, measuring or recording by applying one single type of energy and measuring its conversion into another type of energy
- A61B5/0095—Detecting, measuring or recording by applying one single type of energy and measuring its conversion into another type of energy by applying light and detecting acoustic waves, i.e. photoacoustic measurements
Abstract
A system for detecting a wave occurring in/on a membrane comprises a source (101) for directing an excitation signal obliquely to the membrane and a receiver (102) for measuring interference between a first part of the excitation signal reflected off a front surface of the membrane and a second part of the excitation signal reflected off a rear surface of the membrane. The system comprises a processing device (103) for detecting the wave based on a change in the measured interference. The detection of the wave is based on changes caused by the wave in the optical length of a V-shaped part of a propagation path of the second part of the excitation signal, where the V-shaped part of the propagation path is inside the membrane.
Description
System and method for detecting a wave occurring in/on a membrane Technical field The disclosure relates to a system for detecting a wave occurring infon a membrane, for example in/on the cornea of an eye.
Furthermore, the disclosure relates to a method for detecting a wave occurring in/on a membrane.
Background In many cases, there is a need to detect a wave, such as e.g. a membrane wave or a Lamb wave, occurring in/on a membrane.
The wave can be either a standing wave or a travelling wave.
In this document the word “membrane” is not limited to substantially 2-dimensional structures whose thickness is extremely small, but the word “membrane” can mean any material layer, a sheet, a plate, or another structure whose thickness is significantly smaller than the other dimensions.
Detection of a wave occurring infon a membrane can be utilized for example in eye pressure measurements where an excitation such as e.g. an air impulse, an ultrasonic tone burst, a shock wave, or some other suitable excitation is used to deform a cornea and thereafter an estimate of the eye pressure is obtained based on a wave caused by the excitation in/on the cornea.
A wave occurring in/on a membrane can be detected for example using interferometry where radiation is directed to the membrane under consideration and to a reference reflector.
The wave causes > changes in the optical length of a propagation path of the radiation reflected off a N surface of the membrane.
Thus, the wave causes changes in the interference S between the radiation reflected off the reference reflector and the radiation reflected = off the surface of the membrane.
Therefore, the wave can be detected based on the E 25 changes of the above-mentioned interference. > 3 In many applications, the above-described interferometry-based method for = detecting a wave occurring in/on a membrane is however not free from challenges.
N For example, in conjunction with eye pressure measurements, it can be challenging to keep the reference reflector sufficiently stationary with respect to an eye beingmeasured so that unintentional changes in the position and/or orientation of the reference reflector with respect to the eye do not disturb the eye pressure measurement too much. Thus, there is a need for technical solutions for detecting a wave occurring in/on a membrane so that there is no need for a reference reflector or some other element that must be accurately stationary with respect to the membrane carrying the wave to be detected. Summary The following presents a simplified summary to provide basic understanding of some aspects of different invention embodiments. The summary is not an extensive — overview of the invention. It is neither intended to identify key or critical elements of the invention nor to delineate the scope of the invention. The following summary merely presents some concepts of the invention in a simplified form as a prelude to a more detailed description of exemplifying and non-limiting embodiments of the invention. — In this document, the word “geometric” when used as a prefix means a geometric concept that is not necessarily a part of any physical object. The geometric concept can be for example a geometric point, a straight or curved geometric line, a geometric plane, a non-planar geometric surface, a geometric space, or any other geometric entity that is zero, one, two, or three dimensional. In accordance with the invention, there is provided a new system for detecting a o wave occurring infon a membrane, e.g. in/on the cornea of an eye. The membrane > can be any material layer, a sheet, a plate, or another structure whose thickness is N significantly smaller than the other dimensions. A system according to the invention N comprises:
T a 25 - a source for directing an excitation signal to the membrane, and > 3 - a receiver for measuring interference between a first part of the excitation = signal reflected off a front surface of the membrane and a second part of the N excitation signal reflected off a rear surface of the membrane, and
- a processing device for detecting the wave based on changes in the measured interference.
The source and the receiver are positioned obliquely with respect to each other so that the excitation signal is directed obliquely to the membrane when the receiver receives the reflected first and second parts of the excitation signal.
The detection of the wave occurring on the membrane is based on changes caused by the wave in the length of a V-shaped part of a propagation path of the above- mentioned second part of the excitation signal, wherein the V-shaped part of the propagation path is inside the membrane.
The way how the wave changes the length of the above-mentioned V-shaped part is explained later in this document with reference to figures.
As the detection of the wave is based on the interference between the first part of the excitation signal reflected off the front surface of the membrane and the second part of the excitation signal reflected off the rear surface of the membrane, there is no need for a reference reflector and/or another element that must be accurately stationary with respect to the membrane carrying the wave to be detected.
In accordance with the invention, there is provided also a new method for detecting a wave occurring infon a membrane, e.g. in/on the cornea of an eye.
A method according to the invention comprises: - directing an excitation signal obliquely to the membrane, and 2 S - measuring interference between a first part of the excitation signal reflected N off a front surface of the membrane and a second part of the excitation signal N reflected off a rear surface of the membrane, and = - - detecting the wave based on a change in the measured interference. > 3 25 Various exemplifying and non-limiting embodiments are described in accompanied > dependent claims.
Exemplifying and non-limiting embodiments both as to constructions and to methods of operation, together with additional objects and advantages thereof, are bestunderstood from the following description of specific exemplifying embodiments when read in conjunction with the accompanying drawings. The verbs “to comprise” and “to include” are used in this document as open limitations that neither exclude nor require the existence of un-recited features. The features recited in dependent claims are mutually freely combinable unless otherwise explicitly stated. Furthermore, it is to be understood that the use of “a” or “an”, i.e. a singular form, throughout this document does not exclude a plurality. Brief description of figures Exemplifying and non-limiting embodiments of the invention and their advantages are explained in greater detail below with reference to the accompanying drawings, in which: figure 1a illustrates a system according to an exemplifying and non-limiting embodiment for detecting a wave occurring in/on a membrane, figures 1b-1d illustrate the operational principle of the system illustrated in figure 1a, and figure 2 shows a flowchart of a method according to an exemplifying and non-limiting embodiment for detecting a wave occurring in/on a membrane. Description of exemplifying and non-limiting embodiments o The specific examples provided in the description below should not be construed as N 20 limiting the scope and/or the applicability of the accompanied claims. Lists and S groups of examples provided in the description below are not exhaustive unless S otherwise explicitly stated. = > Figure 1a illustrates a system according to an exemplifying and non-limiting 00 S embodiment for detecting a wave occurring in/on a membrane 107. In the
LO 2 25 exemplifying situation shown in figure 1a, the membrane 107 is the cornea of an N eye 106. The wave that travels along the membrane 107 is illustrated in figures 1b, 1c, and 1d which show a section view of the membrane 107 at different moments of time to, t1, and to, where ta > ti > to. The system illustrated in figure 1a comprises asource 101 for directing an excitation signal to the membrane 107. The source 101 may comprise for example a light source 104 that can be for example a laser source such as e.g. a vertical-cavity surface-emitting laser “VCSEL” for emitting the excitation signal.
In this exemplifying case, the excitation signal is a light beam e.g. 5 alaserbeam.
The source 101 may further comprise a lens system for focusing the light beam to the membrane 107. The light beam is advantageously focused on a front surface of the membrane 107 or behind the front surface.
The front surface is the surface of the membrane 107 at which the excitation signal arrives first.
A diameter of a radiation spot, e.g. a laser spot, on the surface of the membrane 107 canbe e.g. in the range from 0.5 mm to 6 mm.
It is also possible that the excitation signal is some other propagating wave-front e.g. an ultrasound wave-front.
The system comprises a receiver 102 for measuring interference between a first part of the excitation signal reflected off the front surface of the membrane 107 and a second part of the excitation signal reflected off a rear surface of the membrane — 107. In figures 1b-1d, the first part of the excitation signal is depicted with a dashed line arrow and the second part of the excitation signal is depicted with a dash-and- dot line arrow.
In exemplifying cases where the excitation signal is electromagnetic radiation e.g. a laser beam, the receiver 102 may comprise for example a lens system and a multipoint sensor comprising an array of sensor elements 105. Each sensor element can be for example a photo-diode or a photo-transistor.
It is also possible that the receiver 102 comprises a charge-coupled device “CCD”. The system further comprises a processing device 103 for detecting the wave based on changes in the interference measured by the receiver 102. In a system according to = an exemplifying and non-limiting embodiment, the receiver 102 comprises a dual N 25 photodiode or a photodiode array, where the differential sensing of the adjacent = photodiodes is used to improve sensitivity.
E The source 101 and the receiver 102 are positioned obliguely with respect to each © other so that the excitation signal is directed obliquely to the membrane 107 when 3 the receiver 102 receives the reflected first and second parts of the excitation signal. > 30 In a system according to an exemplifying and non-limiting embodiment, the source 101 and the receiver 102 are positioned obliguely with respect to each other so that an angle a between a transmission direction of the source 101 and a receptiondirection of the receiver 102 is in the range from 15 degrees to 120 degrees.
In a system according to an exemplifying and non-limiting embodiment, the angle a is in the range from 45 degrees to 90 degrees.
The detection of the wave is explained below with reference to figures 1b-1d.
In the situation shown in figure 1b, the wave has not yet arrived at the radiated area of the membrane 107. The interference between the first and second parts of the excitation signal is determined by the wavelength of the excitation signal and the length of a V-shaped part A-B-C of the propagation path of the second part of the excitation signal.
In exemplifying cases where the excitation signal is electromagnetic radiation e.g. a laser beam, it is assumed that the term “length” includes the effect of the refraction index of the material of the membrane 107. As shown by figures 1b-1d, the V-shaped part of the propagation path is inside the membrane 107. In the situation shown in figure 1c, the wave has arrived at the excited area of the membrane 107. As illustrated in figures 1b and 1c, the distance A-B is longer in the — situation shown in figure 1c than in the situation shown in figure 1b and the distance B-C is substantially the same in the situations shown in figures 1b and 1c.
In the situation shown in figure 1d, the wave has moved further in the direction of propagation than in the situation shown in figure 1c.
As illustrated in figures 1d-1d, the distances A-B and B-C are shorter in the situation shown in figure 1d than in the situations shown in figures 1b and 1c.
The above-described variation in the length of the V-shaped part A-B-C of the propagation path of the second part of the excitation signal causes changes in the interference between the first and second o parts of the excitation signal.
As illustrated by figures 1b-1d, the variation in the N length of the V-shaped part A-B-C is strongest when a distance between the point S 25 A where the second part of the excitation signal enters the membrane 107 and the S point C where the second part of the excitation signal exits the membrane 107 is E substantially the length of the wave occurring in/on the membrane. 00 3 A system according to an exemplifying and non-limiting embodiment comprises a 2 support structure 108 arranged to mechanically support the source 101 and the N 30 receiver 102 so that the above-mentioned angle a shown in figure 1a is changeable.
This enables a user of the system to select the angle a so that the distance between the point A where the second part of the excitation signal enters the membrane 107and the point C where the second part of the excitation signal exits the membrane 107 is substantially the length of the wave occurring in/on the membrane.
In a system according to an exemplifying and non-limiting embodiment, the processing device 103 is configured to estimate variation rate of the measured interference. The variation rate can be expressed e.g. in Hz. In some exemplifying cases, the variation rate can be for example above 1 kHz.
In a system according to an exemplifying and non-limiting embodiment, the processing device 103 is configured to estimate travelling speed of the wave based on the variation rate of the measured interference and pre-stored data indicative of the length of the wave. It is also possible that there are two measurement spots simultaneously on the membrane a known distance apart from each other, and the travelling speed is estimated based on the known distance and a time difference between respective changes taking place in the interferences measured for the two measurement spots.
In a system according to an exemplifying and non-limiting embodiment, the processing device 103 is configured to control the source 101 to vary the wavelength of the excitation signal and to estimate the thickness of the membrane 107 based on the interference measured with different wavelengths of the excitation signal. The thickness is denoted with T in figures 1b-1d. In this exemplifying case, the source 101 may comprise for example a vertical-cavity surface-emitting laser “VCSEL” for implementing a wavelength sweep of the excitation signal. The wavelength of the O excitation signal emitted by a VCSEL can be changed by changing electric current N of the VCSEL. Thus, a VCSEL can be driven with ramped pulses of electric current S in direct intensity modulation, and the intrinsic property of the VCSEL produces a = 25 —wavelength-swept output through the self-heating effect. The excitation signal E emitted by a VCSEL has a long coherence length which makes it possible to 2 measure thicknesses of membranes whose thicknesses are few millimeters, 3 whereas a wavelength scan obtained by changing electric current of the VCSEL > makes it possible to detect white light interference for coherence widths of few hundreds of micrometers. The system may comprise an airgap for acting as a reference for the thickness determination. Data indicative of the thickness beingdetermined can be obtained with the aid of Fourier transformation of the measured interference signal.
As the measurement is carried out not perpendicularly but obliquely, the effect of the obliqueness i.e. a cosine-error is advantageously compensated for in the thickness estimation.
For another example, the thickness estimation can be based on for example a pre-stored reference model obtained with experiments carried out with reference membranes having predetermined thicknesses, where the reference model is indicative of the behavior of the interference as a function of the wavelength of the excitation signal and as a function of the thickness of the membrane, i.e. the interference = f(A, T), A being the wavelength of the excitation signal and T being the thickness of the membrane.
The reference model can be implemented with e.g. a two-dimensional lookup table.
The effect of the refraction index of the material of the membrane can be included in the reference model.
The thickness of the membrane can be estimated by finding a value for the thickness in the reference model so that the behavior of the interference indicated by the reference model as a function of the wavelength is as close as possible to the behavior of the measured interference as a function of the wavelength.
It is also possible that the thickness of the membrane is estimated with a mathematical model based on the theory of wave optics.
The mathematical model gives the thickness estimate when parameters indicative of the behavior of the measured interference as a function of the wavelength are given as input data.
The processing device 103 can be implemented with one or more processor circuits, each of which can be a programmable processor circuit provided with appropriate o software, a dedicated hardware processor such as for example an application N specific integrated circuit "ASIC”, or a configurable hardware processor such as for S 25 example a field programmable gate array “FPGA”. Furthermore, the processing S device 103 may comprise one or more memory circuits each of which can be for E example a random-access-memory “RAM” circuit. 00 3 Figure 2 shows a flowchart of a method according to an exemplifying and non- 2 limiting embodiment for detecting a wave occurring in/on a membrane.
The method N 30 comprises the following actions: - action 201: directing an excitation signal obliquely to the membrane, and
- action 202: measuring interference between a first part of the excitation signal reflected off a front surface of the membrane and a second part of the excitation signal reflected off a rear surface of the membrane, and - action 203: detecting the wave based on a change in the measured interference. In a method according to an exemplifying and non-limiting embodiment, the excitation signal is directed obliquely to the membrane so that an angle 3 between the arrival direction of the excitation signal at the membrane and a geometric perpendicular of the membrane is in the range from 7 degrees to 60 degrees. The angle Bis illustrated in figures 1b-1d. In a method according to an exemplifying and non-limiting embodiment, the above-mentioned angle B is in the range from 22 degrees to 45 degrees. In a method according to an exemplifying and non-limiting embodiment, the above- mentioned angle B is selected so that a distance between a point where the second part of the excitation signal enters the membrane and another point where the second part of the excitation signal exits the membrane is substantially the length of the wave. A method according to an exemplifying and non-limiting embodiment comprises estimating variation rate of the measured interference. A method according to an exemplifying and non-limiting embodiment comprises oO S estimating travelling speed of the wave based on the variation rate of the measured
N A interference and pre-stored data indicative of the length of the wave.
O = A method according to an exemplifying and non-limiting embodiment comprises = varying a wavelength of the excitation signal and estimating the thickness of the 2 25 membrane based on the measured interference corresponding to different O wavelengths of the excitation signal. 3 In a method according to an exemplifying and non-limiting embodiment, the excitation signal is produced with a laser source, e.g. a vertical-cavity surface- emitting laser.
In a method according to an exemplifying and non-limiting embodiment, the interference is measured with an array of sensor elements. The non-limiting, specific examples provided in the description given above should not be construed as limiting the scope and/or the applicability of the appended claims. Furthermore, any list or group of examples presented in this document is not exhaustive unless otherwise explicitly stated.
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Claims (15)
1. A system for detecting a wave occurring in/on a membrane, the system comprising: - a source (101) for directing an excitation signal to the membrane, and - a receiver (102) for measuring interference between a first part of the excitation signal reflected off a front surface of the membrane and a second part of the excitation signal reflected off a rear surface of the membrane, characterized in that the source and the receiver are positioned obliquely with respect to each other so that the excitation signal is directed obliquely to the membrane when the receiver receives the reflected first and second parts of the excitation signal, and the system comprises a processing device (103) for detecting the wave based on a change in the measured interference.
2. A system according to claim 1, wherein the source and the receiver are positioned obliquely with respect to each other so that an angle (a) between a — transmission direction of the source and a reception direction of the receiver is in a range from 15 degrees to 120 degrees.
3. A system according to claim 2, wherein the source and the receiver are positioned obliquely with respect to each other so that the angle (a) is in a range from 45 degrees to 90 degrees. oO S 20
4 A system according to any of claims 1-3, wherein the system comprises a N support structure (108) arranged to mechanically support the source (101) and the N receiver (102) so that an angle (a) between a transmission direction of the source I and a reception direction of the receiver is changeable. a 3
5. A system according to any of claims 1-4, wherein the processing device is S 25 configured to control the source to vary a wavelength of the excitation signal and to Q estimate a thickness (T) of the membrane based on the interference measured with different wavelengths of the excitation signal.
6. A system according to any of claims 1-5, wherein the source (101) comprises a laser source.
7. A system according to claim 6, wherein the laser source is a vertical-cavity surface-emitting laser.
8 A system according to any of claims 1-7, wherein the receiver comprises an array of sensor elements (105).
9. A method for detecting a wave occurring in/on a membrane (107), the method comprising: - directing (201) an excitation signal to the membrane, and - measuring (202) interference between a first part of the excitation signal reflected off a front surface of the membrane and a second part of the excitation signal reflected off a rear surface of the membrane, characterized in that the excitation signal is directed (201) obliquely to the membrane, and the method comprises detecting (203) the wave based on a change — in the measured interference.
10. A method according to claim 9, wherein the excitation signal is directed obliquely to the membrane so that an angle (3) between an arrival direction of the excitation signal at the membrane and a geometric perpendicular of the membrane is in a range from 7 degrees to 60 degrees oO N 20
11. A method according to claim 10, wherein the angle (B) is in a range from 22
QA Q degrees to 45 degrees.
N I
12. A method according to any of claims 9-11, wherein the method comprises a © selecting an angle (B) between an arrival direction of the excitation signal at the 3 membrane and a geometric perpendicular of the membrane so that a distance o S 25 between a point (A) where the second part of the excitation signal enters the
N membrane and another point (C) where the second part of the excitation signal exits the membrane is substantially a length of the wave.
13. A method according to any of claims 9-12, wherein the method comprises varying a wavelength of the excitation signal and estimating a thickness of the membrane based on the measured interference corresponding to different wavelengths of the excitation signal.
14. A method according to any of claims 9-13, wherein the excitation signal is produced with a laser source.
15. A method according to any of claims 9-14, wherein the interference is measured with an array of sensor elements.
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Priority Applications (6)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FI20195098A FI20195098A1 (en) | 2019-02-12 | 2019-02-12 | System and method for detecting a wave occurring in/on a membrane |
| CN202080013516.3A CN113424015B (en) | 2019-02-12 | 2020-02-05 | System and method for detecting waves in/on a membrane |
| ES20708531T ES2936798T3 (en) | 2019-02-12 | 2020-02-05 | System and method for detecting a wave produced in/on a membrane |
| EP20708531.7A EP3924690B1 (en) | 2019-02-12 | 2020-02-05 | System and method for detecting a wave occurring in/on a membrane |
| PCT/FI2020/050069 WO2020165495A1 (en) | 2019-02-12 | 2020-02-05 | System and method for detecting a wave occurring in/on a membrane |
| US17/430,046 US20220113125A1 (en) | 2019-02-12 | 2020-02-25 | System and method for detecting a wave occurring in/on a membrane |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FI20195098A FI20195098A1 (en) | 2019-02-12 | 2019-02-12 | System and method for detecting a wave occurring in/on a membrane |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| FI20195098A1 true FI20195098A1 (en) | 2020-08-13 |
Family
ID=69740380
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| FI20195098A FI20195098A1 (en) | 2019-02-12 | 2019-02-12 | System and method for detecting a wave occurring in/on a membrane |
Country Status (6)
| Country | Link |
|---|---|
| US (1) | US20220113125A1 (en) |
| EP (1) | EP3924690B1 (en) |
| CN (1) | CN113424015B (en) |
| ES (1) | ES2936798T3 (en) |
| FI (1) | FI20195098A1 (en) |
| WO (1) | WO2020165495A1 (en) |
Family Cites Families (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7292349B2 (en) * | 2001-10-26 | 2007-11-06 | University Of Rochester | Method for biomolecular sensing and system thereof |
| US20040193033A1 (en) * | 2002-10-04 | 2004-09-30 | Badehi Avner Pierre | Noninvasive methods and apparatuses for measuring the intraocular pressure of a mammal eye |
| US20050030473A1 (en) * | 2003-06-12 | 2005-02-10 | Welch Allyn, Inc. | Apparatus and method for determining intraocular pressure and corneal thickness |
| DE102008008732A1 (en) * | 2008-02-11 | 2009-08-13 | Carl Zeiss Meditec Ag | Method and device for determining corneal radii |
| FI20135401L (en) * | 2013-04-19 | 2014-10-20 | Garuda Oy | Measuring procedure and measuring arrangement for utilizing electromagnetic waves |
| FI20145205L (en) * | 2014-03-04 | 2015-09-05 | Photono Oy | Method and system for intraocular pressure measurements |
| US11006828B2 (en) * | 2014-07-17 | 2021-05-18 | 1 Sonic Medical Corporation, S.A.S. | Measurement of ocular parameters using vibrations induced in the eye |
| EP3344116A1 (en) * | 2015-09-03 | 2018-07-11 | Photono Oy | Method and arrangement for eye measurements |
| CN107664476B (en) * | 2016-07-28 | 2020-06-05 | 中微半导体设备(上海)股份有限公司 | Optical detection device and detection method for semiconductor equipment |
| JP6550101B2 (en) * | 2017-07-13 | 2019-07-24 | Ｊｆｅテクノリサーチ株式会社 | Film thickness measuring method and film thickness measuring apparatus |
| CN107607051B (en) * | 2017-10-26 | 2019-07-30 | 京东方科技集团股份有限公司 | A kind of film thickness detecting device |
-
2019
- 2019-02-12 FI FI20195098A patent/FI20195098A1/en not_active Application Discontinuation
-
2020
- 2020-02-05 ES ES20708531T patent/ES2936798T3/en active Active
- 2020-02-05 EP EP20708531.7A patent/EP3924690B1/en active Active
- 2020-02-05 WO PCT/FI2020/050069 patent/WO2020165495A1/en unknown
- 2020-02-05 CN CN202080013516.3A patent/CN113424015B/en active Active
- 2020-02-25 US US17/430,046 patent/US20220113125A1/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| CN113424015A (en) | 2021-09-21 |
| CN113424015B (en) | 2023-06-20 |
| EP3924690B1 (en) | 2022-12-21 |
| EP3924690A1 (en) | 2021-12-22 |
| WO2020165495A1 (en) | 2020-08-20 |
| ES2936798T3 (en) | 2023-03-22 |
| US20220113125A1 (en) | 2022-04-14 |
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